Claims
- 1. A mobile radio communication apparatus, having a communication function adaptable to both an analog mode and a digital mode, for carrying out communications with one of radio base stations capable of communicating in at least the analog mode, said apparatus comprising:
signal receiving means for receiving a signal representing that a communication can be carried out in the digital mode from a radio base station capable of communicating in both the analog mode and the digital mode, the signal being received in the analog mode; detecting means for detecting a strength of the signal received from the radio base station; and shifting means for shifting a mode of communication services into the digital mode from the analog mode in accordance with the strength, when the signal is received.
- 2. A mobile radio communication apparatus according to claim 1, wherein the shifting means shifts the mode of communication services into the digital mode when the strength is at a predetermined level or higher, and maintains the analog mode when the strength is lower than the predetermined level.
- 3. A mobile radio communication apparatus according to claim 1, wherein the digital mode is the CDMA mode.
- 4. A mobile radio communication apparatus according to claim 1, wherein the analog mode is the AMPS mode.
- 5. A mobile radio communication apparatus according to claim 1, wherein the signal is an analog signal.
- 6. A mobile radio communication apparatus according to claim 1, wherein said shifting means includes transmitting means for transmitting to the radio base station a location registration signal for registering a location of the mobile radio communication apparatus in order to establish a communication in the digital mode in accordance with the strength.
- 7. A mobile radio communication apparatus according to claim 6, wherein said shifting means further includes:
seizing means for seizing a control channel for controlling a communication in the digital mode in accordance with the strength; and control signal receiving means for receiving a control signal on the sized control channel, the control signal being transmitted from the radio base station.
- 8. A control method for controlling a mobile radio communication apparatus having a communication function adaptable to both an analog mode and a digital mode and a function for receiving, from a radio base station in the analog mode, a signal representing that a communication can be carried out in the digital mode, said method comprising the steps of:
detecting a strength of the message signal received from the radio base station; and shifting a mode of communication services into the digital mode from the analog mode in accordance with the strength, when the message signal is received.
- 9. A control method according to claim 8, wherein the mode of communication services is shifted into the digital mode when the strength is at a predetermined level or higher, and the analog mode is maintained when the strength is lower than the predetermined level.
- 10. A control method according to claim 8, wherein the digital mode is the CDMA mode.
- 11. A control method according to claim 8, wherein the analog mode is the AMPS mode.
- 12. A control method according to claim 8, wherein the signal is an analog signal.
- 13. A control method for controlling a mobile radio communication apparatus having a communication function adaptable to both an analog mode and a digital mode and a function for receiving, from a radio base station in the analog mode, a signal representing that a communication can be carried out in the digital mode, said method comprising the steps of:
detecting a strength of the signal received from the radio base station; and performing a control for transmitting to the radio base station a location registration signal for registering a location of the mobile radio communication apparatus in order to establish a communication in the digital mode in accordance with the strength, when the signal is received.
- 14. A control method according to claim 13, further comprising the steps of:
seizing a control channel for controlling a communication in the digital mode in accordance with the strength; and receiving a control signal on the control channel, the control signal being transmitted from the radio base station.
- 15. A control method according to claim 13, wherein a mode of communication services is shifted to the digital mode when the strength is at a predetermined level or higher, and the analog mode is maintained when the strength is lower than the predetermined level.
- 16. A control method according to claim 13, wherein the digital mode is the CDMA mode.
- 17. A control method according to claim 13, wherein the analog mode is the AMPS mode.
- 18. A control method according to claim 13, wherein the signal is an analog signal.
- 19. A control method for controlling a mobile radio communication apparatus adaptable to both an analog mode and a digital mode, for carrying out a communication with a radio base station capable of carrying out a communication at least in the analog mode, said method comprising the steps of:
receiving, from the radio base station in the analog mode, a message signal representing that a communication can be carried out in the digital mode; detecting a strength of the signal received from the radio base station; and shifting a mode of communication services into the digital mode in accordance with the strength, when the signal is received.
- 20. A control method according to claim 19, wherein, in said shifting step, the mode of communication services is shifted into the digital mode when the strength is at a predetermined level or higher, and the analog mode is maintained when the strength is lower than the predetermined level.
- 21. A control method according to claim 19, wherein the digital mode is the CDMA mode.
- 22. A control method according to claim 19, wherein the analog mode is the AMPS mode.
- 23. A control method according to claim 19, wherein the signal is an analog signal.
- 24. A control method according to claim 19, wherein said shifting step includes a step of transmitting to the radio base station a location registration signal for registering a location of the mobile radio communication apparatus in order to establish a communication in the digital mode in accordance with the strength.
- 25. A mobile radio communication apparatus according to claim 24, wherein said shifting step further includes the steps of:
seizing a control channel for controlling a communication in the digital mode in accordance with the strength; and receiving a control signal on the control channel, the control signal being transmitted from the radio base station.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-341575 |
Dec 1999 |
JP |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-341575, filed Dec. 1, 1999, the entire contents of which are incorporated herein by reference.